Research and development in Bluetooth Low Energy is a continuing process undertaken by the Bluetooth SIG. Many companies, in collaboration with the SIG, are working to stretch the limits of the technology.
To understand the scale of research and development, you can refer to the list of contributors to Bluetooth 5:
This list is available on the Bluetooth SIG's website. You can see that a broad range of people contributed to the development of Bluetooth 5. The list goes from Qualcomm Technologies, Inc. to Texas Instruments. With their collaboration, they managed to achieve extraordinary advancements in Bluetooth technology. The proof of this is the significant increase in the range and speed of the latest version of Bluetooth.
The SIG also encourages research from students and independent research companies to improve the health of Bluetooth technology...
